Retread-vulcanizer.



P H` WILKENSONA RETREAD VULCANlZEH APPLICATION man Auazl, i918.

12297;? Paten-ted Mar. 18,1919

Fay, /l

l) Q if? /f WITNESS: INVENTOR.

UNITED sTATEs PATENT oEEIoE.

RETREAD-VULCANIZER.

Patented Mar. 1s, 1919.

Application filed August 21, 1918. Serial No. 250,778.

1,297,765 Speccatiouof Letters Patent.

To all whom t may concern: and I have shown the,y details of the coolingBe it known that I, PAUL H. WILKINSON, end in Figs. 2 andy 3. Thecooling end 10 a. citizen of the United States, residing at consists ofa comparatively thin shell 11 San Bernardino, in the county of SanBerformed of aluminum, cast-iron, or the like,

5 nardino and Sta-te of California, have inand the shell 11 forms anextension 12 of vented new and useful Improvements in the mold cavity 3.Radiating ribs 13 ex- Retread-Vulcanizers, of which the following tendoutwardly from the shell 11. A flange is a specification. 14 extendsoutwardly' from the end of the My invention relates to retreadvulcanshell and the shell 11 tapers from the flange 65 izers, andconsists of the novel features 14 to the outer end, and the flange 14conherein shown, described and claimed.

My object is to make cooling ends,so as to taper and overlap the curesand prevent lthe hot rubber from running out of the ends of themolds.

' neots the inner ends of the radiating ribs 13. Ears 15 extendoutwardly from the flange 14, andthe face 16 of the flange 14 and theears 15 fits the end face 17 of the mold 1. A thick pad 18 of asbestospaper or other Figure 1 is a sideelevation of a retread `suitablenon-heat conducting, material is placed between the faces 16 and 17. Cap

vulcanizer provided with cooling ends in accordance with the principlesof my invention, parts of the tire casing being broken away.

Fig. 2 is a cross sectional detail on theline Fig. 3 is a verticallongitudinal sectiona detail on the line 3 3 of Fig. 2.

pression plate 7 is placed against the bag 6,

and the compression'screws 8 are operated to press the plate 7 againstthe bag 6 and press the bag against the tire casing 4 to press the tirecasing 4 firmly against the gum rubber and hold the gum rubber until itis cured. The mold 1 is designed to cure .a complete retread upon a tirecasing 4 at three operations. In actual Ipractice vwhen the gum rubber 5is in theniold cavity 3 and being cured the gum rubber melts, and moreor less of the gum rubber runs out of the ends of mold' 1; furthermorethe gum rubber is cured thoroughly up to a fixed line, and this fixedline is marred by the gum running out of the end of the mold and theresult is that the finished retread lshows scars between the ends of thecures, and the joints between the cures are more or less defective. l

In order to overcome thls difi'culty I have devised the cooling ends and10. The cooling ends 9 and 10 are substantially alike,V

screws 19 are inserted through the ears 15, through the pad 18 andtapped into the end of the mold l.

In the use of my cooling ends, the bag 6 2-2 of Figs. 1 and 3, andlooking iii-the ,fands-the compression plate 7 should be long idirection indicated by the arrows.

cooling'ends, so as to hold the tire casing 4 and the retread rubber 5firmly in the eX- tension cavity 12, and prevent the hot rubber in thecavity 3 from running out of the mold 1. v

' The extension cavity 12 should match with the cavity 3. As shown thecavity 3 and the extension cavity 12 are for plain treads.

A If the mold is to be equipped for non-skid treads, then the matrixface of the extension cavity 12 should match the matrix face of the moldcavity 3, and if a shellor removable matrix is used, the shell orremovable matrix should extend to the outer ends of the cooling ends 9and 10.

In the practical operation of the cooling ends 9 and 10 the heat fromthe mold 1 will be partly communicated through the pad 18 "if enough to.extend to the outer ends ofthe f1 melt the gum rubber, andthe jointbetween the cured rubber in the cavity 3 and the uncured rubber outsideof the outer end of the shell 11 will be tapered, so that when thebetween two cures will be overlapped or spliced instead of beingstraight, as would 11.05;' tire casing and retread is finished thejoints 'F Q n l 1,297,765

ing 4, to the retreadt and prevent the hotA rubber from expanding andproducing a spongy product.

Various vchanges may be made Without departing from the spirit of myinventionas Claimed. v v.

I claim:

A cooling end for a retread vulcanizer I i comprising, a shel1 formingan extension 10 cavity; radlatmg ribs elxtendlng from the shell; anattaching flange extending fromv flange and ears; and cap screwsinserted l? through the flange and pad, and adapted to be screwed intothe end of the mold.- l

In testimony whereof I have signed my name to this specication'.

PAUL H.WILKINSON.

